From patchwork Thu Jan 17 20:59:28 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [for-1.4, 02/12] target-i386: Don't set any KVM flag by default if KVM is disabled Date: Thu, 17 Jan 2013 10:59:28 -0000 From: Eduardo Habkost X-Patchwork-Id: 213370 Message-Id: <1358456378-29248-3-git-send-email-ehabkost@redhat.com> To: qemu-devel@nongnu.org, Anthony Liguori Cc: Igor Mammedov , =?UTF-8?q?Andreas=20F=C3=A4rber?= This is a cleanup that tries to solve two small issues: - We don't need a separate kvm_pv_eoi_features variable just to keep a constant calculated at compile-time, and this style would require adding a separate variable (that's declared twice because of the CONFIG_KVM ifdef) for each feature that's going to be enabled/disable by machine-type compat code. - The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features even when KVM is disabled at runtime. This small incosistency in the cpuid_kvm_features field isn't a problem today because cpuid_kvm_features is ignored by the TCG code, but it may cause unexpected problems later when refactoring the CPUID handling code. This patch eliminates the kvm_pv_eoi_features variable and simply uses kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it enables kvm_pv_eoi only if KVM is enabled. I believe this makes the behavior of enable_kvm_pv_eoi() clearer and easier to understand. Signed-off-by: Eduardo Habkost Acked-by: Gleb Natapov Reviewed-by: Marcelo Tosatti --- Cc: kvm@vger.kernel.org Cc: Michael S. Tsirkin Cc: Gleb Natapov Cc: Marcelo Tosatti Changes v2: - Coding style fix Changes v3: - Eliminate #ifdef by using the fake KVM_FEATURE_PV_EOI #define Changes v4: - Check kvm_enabled() when actually using kvm_default_features - Eliminate Yet Another #ifdef by using the fake KVM_FEATURE_* #defines on kvm_default_features initialization Changes v5: - Rebase and move the kvm_enabled() check to cpu_x86_register() --- target-i386/cpu.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 333745b..754eb6f 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -206,22 +206,16 @@ typedef struct model_features_t { int check_cpuid = 0; int enforce_cpuid = 0; -#if defined(CONFIG_KVM) static uint32_t kvm_default_features = (1 << KVM_FEATURE_CLOCKSOURCE) | (1 << KVM_FEATURE_NOP_IO_DELAY) | (1 << KVM_FEATURE_CLOCKSOURCE2) | (1 << KVM_FEATURE_ASYNC_PF) | (1 << KVM_FEATURE_STEAL_TIME) | (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT); -static const uint32_t kvm_pv_eoi_features = (0x1 << KVM_FEATURE_PV_EOI); -#else -static uint32_t kvm_default_features = 0; -static const uint32_t kvm_pv_eoi_features = 0; -#endif void enable_kvm_pv_eoi(void) { - kvm_default_features |= kvm_pv_eoi_features; + kvm_default_features |= (1UL << KVM_FEATURE_PV_EOI); } void host_cpuid(uint32_t function, uint32_t count, @@ -1602,7 +1596,9 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model) goto out; } - def->kvm_features |= kvm_default_features; + if (kvm_enabled()) { + def->kvm_features |= kvm_default_features; + } def->ext_features |= CPUID_EXT_HYPERVISOR; if (cpu_x86_parse_featurestr(def, features) < 0) {